diff --git a/NzbDrone.Core.Test/ProviderTests/RootDirProviderTest.cs b/NzbDrone.Core.Test/ProviderTests/RootDirProviderTest.cs
index a8ae8a867..433155a40 100644
--- a/NzbDrone.Core.Test/ProviderTests/RootDirProviderTest.cs
+++ b/NzbDrone.Core.Test/ProviderTests/RootDirProviderTest.cs
@@ -92,7 +92,6 @@ namespace NzbDrone.Core.Test.ProviderTests
         }
 
 
-
         [Test]
         public void None_existing_folder_returns_empty_list()
         {
@@ -123,5 +122,16 @@ namespace NzbDrone.Core.Test.ProviderTests
                 );
         }
 
+        [Test]
+        public void adding_duplicated_root_folder_should_throw()
+        {
+            WithRealDb();
+
+            //Act
+            var rootDirProvider = Mocker.Resolve<RootDirProvider>();
+            rootDirProvider.Add(new RootDir { Path = @"C:\TV" });
+            Assert.Throws<InvalidOperationException>(() => rootDirProvider.Add(new RootDir { Path = @"C:\TV" }));
+        }
+
     }
 }
\ No newline at end of file
diff --git a/NzbDrone.Core/Providers/RootDirProvider.cs b/NzbDrone.Core/Providers/RootDirProvider.cs
index 2b07f459b..ee30580b3 100644
--- a/NzbDrone.Core/Providers/RootDirProvider.cs
+++ b/NzbDrone.Core/Providers/RootDirProvider.cs
@@ -34,7 +34,15 @@ namespace NzbDrone.Core.Providers
 
         public virtual void Add(RootDir rootDir)
         {
-            ValidatePath(rootDir);
+            if (String.IsNullOrWhiteSpace(rootDir.Path) || !Path.IsPathRooted(rootDir.Path))
+                throw new ArgumentException("Invalid path");
+
+            if (!_diskProvider.FolderExists(rootDir.Path))
+                throw new DirectoryNotFoundException("Can't add root directory that doesn't exist.");
+
+            if (GetAll().Exists(r => DiskProvider.PathEquals(r.Path, rootDir.Path)))
+                throw new InvalidOperationException("Root directory already exist.");
+
             _database.Insert(rootDir);
         }
 
@@ -43,19 +51,6 @@ namespace NzbDrone.Core.Providers
             _database.Delete<RootDir>(rootDirId);
         }
 
-        private void ValidatePath(RootDir rootDir)
-        {
-            if (String.IsNullOrWhiteSpace(rootDir.Path) || !Path.IsPathRooted(rootDir.Path))
-            {
-                throw new ArgumentException("Invalid path");
-            }
-
-            if (!_diskProvider.FolderExists(rootDir.Path))
-            {
-                throw new DirectoryNotFoundException("Can't add root directory that doesn't exist.");
-            }
-        }
-
         public List<String> GetUnmappedFolders(string path)
         {
             Logger.Debug("Generating list of unmapped folders");
diff --git a/NzbDrone.Core/Providers/SmtpProvider.cs b/NzbDrone.Core/Providers/SmtpProvider.cs
index 2ff2eb26b..c22f13b9c 100644
--- a/NzbDrone.Core/Providers/SmtpProvider.cs
+++ b/NzbDrone.Core/Providers/SmtpProvider.cs
@@ -93,6 +93,7 @@ namespace NzbDrone.Core.Providers
             return Send(email, _configProvider.SmtpServer, _configProvider.SmtpPort, _configProvider.SmtpUseSsl, credentials);
         }
 
+        //TODO: make this throw instead of return false.
         public virtual bool Send(MailMessage email, string server, int port, bool ssl, NetworkCredential credentials)
         {
             try